|Publication number||US6921036 B2|
|Application number||US 10/110,095|
|Publication date||Jul 26, 2005|
|Filing date||Jul 20, 2001|
|Priority date||Aug 5, 2000|
|Also published as||DE10038293A1, DE50112076D1, EP1309790A1, EP1309790B1, US20030079714, WO2002012710A1|
|Publication number||10110095, 110095, PCT/2001/2766, PCT/DE/1/002766, PCT/DE/1/02766, PCT/DE/2001/002766, PCT/DE/2001/02766, PCT/DE1/002766, PCT/DE1/02766, PCT/DE1002766, PCT/DE102766, PCT/DE2001/002766, PCT/DE2001/02766, PCT/DE2001002766, PCT/DE200102766, US 6921036 B2, US 6921036B2, US-B2-6921036, US6921036 B2, US6921036B2|
|Original Assignee||Robert Bosch Gmbh|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (12), Non-Patent Citations (1), Referenced by (1), Classifications (15), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates to a fuel injector.
Fuel injectors, which are preferably suitable for direct injection of fuel into the combustion chamber of an internal combustion engine, are usually equipped with valve needles which are either riveted to an armature, which is actuated by the valve needle, or they are connected to the armature in a friction-locking or form-locking manner by two sleeves welded to the valve needle.
One disadvantage of the method of riveting the armature onto the valve needle is in particular that high forces are needed to reliably join the valve needle and the armature. This may easily result in deformation of or cracks in the material of the armature or the valve needle, which may later result in malfunctions in operation of the fuel injector.
If the armature and the valve needle are joined by flanges welded to the valve needle, the manufacturing and installation complexity due to the large number of components which are assembled is a particular disadvantage.
The fuel injector according to the present invention has the advantage over the related art that no welding or riveting of the two components is necessary due to a conical design of the part of the valve needle which passes through the armature and a corresponding shaping of the recess which accommodates the valve needle.
It is advantageous in particular that when the fuel injector is closed or is being closed, the conical connection is reinforced by the force of the restoring spring.
The special shape of the conical area of the valve needle as well as the matching shape of the recess in the armature ensures to advantage that, also when opening the valve, the conical connection is stressed only by the needle's own weight and by low hydraulic forces of the fuel flowing around the armature.
It is advantageous in particular that the manufacture of the assembly composed of the valve needle and the armature may be accomplished rapidly and inexpensively, because the two parts are easy to manufacture and no other components which would have to be joined to the valve needle by welding or other complicated joining procedures are needed.
It is also advantageous that the inlet end of the valve needle which projects beyond the armature surface may provide centering for the restoring spring, which is supported on the inlet side of the armature surface.
Before describing two embodiments of a valve needle 3 and an armature 20 of a fuel injector according to the present invention on the basis of
Fuel injector 1 is designed in the form of a fuel injector for fuel injection systems of engines having fuel mixture compression and spark ignition. Fuel injector 1 is suitable in particular for direct injection of fuel into a combustion chamber of an engine.
Fuel injector 1 has a nozzle body 2 in which a valve needle 3 is situated. Valve needle 3 is mechanically linked to a valve-closure member 4 which cooperates with a valve-seat surface 6 provided on a valve seat body 5 to form a sealing seat. Fuel injector 1 is an inwardly opening fuel injector 1 in this embodiment and has an injection orifice 7. Nozzle body 2 is sealed by a gasket 8 against stationary pole 9 of a solenoid 10. Solenoid 10 is encapsulated in a coil housing 11 and is wound on a field spool 12 which is in contact with an internal pole 13 of solenoid 10. Internal pole 13 and stationary pole 9 are separated by a gap 26 and are supported on a connecting component 29. Solenoid 10 is energized via a line 19 by an electric current via an electric plug-in contact 17. Plug-in contact 17 is encased in a plastic sheathing 18, which may be integrally molded on internal pole 13.
Valve needle 3 is guided in a valve needle guide 14 which is designed as a disk. A matching adjusting disk 15 is used to adjust the lift. An armature 20 is situated on the other side of adjusting disk 15. Via a first flange 21, the armature is in a friction-locking connection with valve needle 3, which is joined by a weld 22 to first flange 21. A restoring spring 23, which is pre-stressed by a sleeve 24 in the present design of fuel injector 1, is supported on first flange 21.
A second flange 31, which is also joined to valve needle 3 by a weld 33, functions as the lower armature stop. An elastic intermediate ring 32 which sits on second flange 31 prevents rebound when fuel injector 1 closes.
Fuel channels 30 a through 30 c convey fuel which is supplied through a central fuel feed 16 and is filtered through a filter element 25, to injection orifice 7, these channels running in valve needle guide 14, in armature 20 and on valve seat body 5. Fuel injector 1 is sealed from a cylinder head (not shown) and a distributor line by a gasket 28.
In the resting state of fuel injector 1, armature 20 is acted upon by restoring spring 23 against its direction of lift via first flange 21 on valve needle 3, so that valve-closure member 4 is held in sealing contact on valve seat 6. When solenoid 10 is energized, it builds up a magnetic field which moves armature 20 in the direction of lift against the spring force of restoring spring 23, the lift being predetermined by a working gap 27 between internal pole 12 and armature 20 in the resting position. Armature 20 also entrains flange 21, which is welded to valve needle 3, and thus also valve needle 3 in the direction of lift. Valve-closure member 4, which is mechanically linked with valve needle 3, is lifted up from valve-seat surface 6, and fuel carried through to injection orifice 7 via fuel channels 30 a through 30 c is injected.
When the coil current is turned off, armature 20 drops back from internal pole 13 due to the pressure of restoring spring 23 onto first flange 21 after the magnetic field has been reduced sufficiently, so that valve needle 3 moves against the direction of lift. Therefore, valve-closure member 4 comes to rest on valve-seat surface 6 and fuel injector 1 is closed.
In a detail of a sectional view,
In contrast with the embodiment of a fuel injector 1 illustrated in
As shown in
Recess 39 of armature 20 may be designed so that only a portion of its axial extent is conical.
Valve needle 3 thus passes through central recess 39 of armature 20 and projects at an inlet end 38 beyond an inlet end face 34 of armature 20. Inlet end 38 of valve needle 3 is cylindrical in the present first embodiment, the diameter of inlet end 38 being somewhat smaller than the diameter of outlet end 35 of valve needle 3 according to the taper of valve needle 3 due to conical area 37.
Restoring spring 23 is supported directly on inlet end face 34 of armature 20, in contrast with the embodiment in
Valve needle 3 and armature 20 are connected by a single joining operation. In doing so, conical recess 39 in armature 20 is positioned over valve needle 3 until conical area 37 of valve needle 3 is in conical recess 39 in armature 20. Then armature 20 is pressed onto valve needle 3 by a defined force.
When fuel injector 1 is opened, armature 20 is pulled in the direction of internal pole 13 (not shown). The conical connection between valve needle 3 and armature 20 is acted upon only by the weight of valve needle 3 and by minor hydraulic forces exerted by fuel flowing through fuel injector 1 on inlet end face 34 of armature 20. When fuel injector 1 closes, the conical connection is supported by the high force of restoring spring 23, which is supported on the inlet end face 34 of armature 20, because restoring spring 23 presses armature 20 onto valve needle 3 and thus presses valve needle 3 into the sealing seat.
In the same type of diagram as
In contrast with the first embodiment in
Inlet end 38 of valve needle 3 again projects beyond inlet end face 34 of armature 20 and thus ensures the centering of restoring spring 23.
In the embodiments of valve needle 3 illustrated in
The present invention is not limited to the embodiments illustrated here and is also applicable to other valve needles 3, e.g., double needles and hollow needles in combination with any armature designs, e.g., submersible armatures and flat-type armatures, as well as any fuel injector designs.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US5114077 *||Dec 12, 1990||May 19, 1992||Siemens Automotive L.P.||Fuel injector end cap|
|US5236173 *||Mar 11, 1992||Aug 17, 1993||Siemens Automotive L.P.||Armature bounce damper|
|US5315278 *||Jul 30, 1992||May 24, 1994||Siemens Automotive L.P.||Filament magnetic flux circuit|
|US5613640||Aug 15, 1995||Mar 25, 1997||Zexel Corporation||Fuel injection valve|
|US5645226 *||Feb 13, 1995||Jul 8, 1997||Siemens Automotive Corporation||Solenoid motion initiator|
|US6145761 *||Jul 28, 1998||Nov 14, 2000||Robert Bosch Gmbh||Fuel injection valve|
|US6494388 *||Oct 13, 1999||Dec 17, 2002||Robert Bosch Gmbh||Fuel injection valve|
|DE19828849A1||Jun 27, 1998||Dec 30, 1999||Bosch Gmbh Robert||Fuel injection valve with integrated spark plug for direct injection of fuel into combustion chamber of IC engine and its ignition|
|DE19849210A1||Oct 26, 1998||Apr 27, 2000||Bosch Gmbh Robert||Fuel injection valve for internal combustion engine fuel injection system has armature movable between two stops, damping spring arranged between second stop and armature|
|JPS60164659A||Title not available|
|JPS60192873A||Title not available|
|JPS60192874A||Title not available|
|1||*||Beitz et al., DUBBLE Pocketbook For Mechanical Engineering, 1997 Stringer, Berlin, ISBN No. 3-540-6247-8, 19<SUP>th </SUP>Ed., Cone Interference Connections, p. G27, par. 1.4, p. G30, par. 1.4.3, figure 33G.*.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|CN103291514B *||Feb 4, 2013||Jan 20, 2016||株式会社京浜||电磁式燃料喷射阀|
|U.S. Classification||239/585.5, 239/533.2, 239/533.3, 239/533.9, 239/88, 239/585.1|
|International Classification||F02M61/16, F02B75/12, F02M51/06|
|Cooperative Classification||Y02T10/123, F02M51/0671, F02B2075/125, F02M61/168|
|European Classification||F02M51/06B2E2, F02M61/16H|
|Sep 23, 2002||AS||Assignment|
Owner name: ROBERT BOSCH GMBH, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:REITER, FERDINAND;REEL/FRAME:013309/0586
Effective date: 20020819
|Jan 13, 2009||FPAY||Fee payment|
Year of fee payment: 4
|Mar 11, 2013||REMI||Maintenance fee reminder mailed|
|Jul 26, 2013||LAPS||Lapse for failure to pay maintenance fees|
|Sep 17, 2013||FP||Expired due to failure to pay maintenance fee|
Effective date: 20130726